This disclosure relates to polycarbonates, and in particular to polycarbonate-poly(alkylene oxide) copolymers, blends with polycarbonates, and uses thereof.
Polycarbonates are useful in the manufacture of articles and components for a wide range of applications including medical devices. Polycarbonates having excellent attributes including an inherently (i.e., permanently) hydrophilic surface are particularly desirable for such devices. A permanently hydrophilic polycarbonate surface is important for applications where the ability of water to wet a surface is critical. Such applications include filters and membranes where a hydrophilic surface is needed to prevent air bubbles and to improve flow through a membrane.
It is known in the art that copolycarbonates can be made with poly(ethylene oxide) (also referred to herein as “poly(ethylene glycol)”) blocks to improve surface wettability. At least in part because of their good hemocompatibility properties, such polycarbonates are useful in medical packaging applications. However, polycarbonates with PEG blocks can have low glass transition temperatures and are therefore less able to withstand high temperature and high pressure sterilization (autoclave) conditions without deformation compared to polycarbonates having none or a lower amount of units derived from ethylene oxide. Conversely, increased levels of carbonate units based on bisphenols such as bisphenol A that would provide the requisite thermal deformation resistance generally have higher surface contact angle and can result in reduced hemocompatibility. However, increased levels of the ethylene oxide units can also lead to increased haze in the compositions.
There accordingly remains a need in the art for polycarbonates that have improved surface wettability, together with other advantageous properties, such as thermal stability, hemocompatibility, anti-fogging, and improved transparency.